Abstract

The modification of thermoluminescence (TL) and photoluminescence(PL) properties of nanoparticles by swift heavy ions (SHI), irradiation is studied. Pellets form of the nanomaterials were irradiated by 48 MeV , 75 MeV , and 90 MeV ion beams. The fluence range is . The modification in TL glow curves of the nanomaterialsirradiated by , , and ion beams are essentially similar to those induced by -ray irradiation. These glow curves have single peaks at around 427 K with a small variation in their positions by around . The TL intensity of the ion beamsirradiatednanomaterials is found to decease, while going from low to high atomic number ions (i.e., ). The TL response curve of the pellets irradiated by ions is linear in the whole range of studied fluences. The curves for and irradiated samples are linear at lower fluences and then saturate at higher fluence. These results for the nanomaterials are much better than that of the corresponding microcrystalline samples irradiated with a ion. The curves were linear up to the fluence and then become sublinear at higher fluences. The TL efficiency values of nanoparticlesirradiated by 48 MeV , 75 MeV , and 90 MeV ion beams have been measured relative to rays of and are found to be 0.515, 0.069, and 0.019, respectively. This value for the ion (0.515) is much higher than that of the corresponding microcrystalline material (0.0014). These superiorities for the nanomaterials make nanophosphor a suitable candidate for detecting the doses of swift heavy ions. PL studies on the ion beamsirradiated and unirradiated nanoparticles show a single band at 384 nm, which could be assigned to emission, while the microcrystalline form of this material shows emission at 436 nm. This wide blueshift in PL of the nanomaterial could be attributed to the extension of the band gap of due to the absence of crystal field effects.

Received 07 June 2007Accepted 20 July 2007Published online 17 September 2007

Acknowledgments:

The authors are thankful to the Department of Science and Technology (DST), New Delhi, India and the Russian Academy of Sciences (RAS), Moscow, Russia for providing financial assistance under Project No. A.2.53. The authors are also thankful to the Director of the Inter-University Accelerator Centre (IUAC), New Delhi for providing beams from 15 UD Pelletron for successful completion of these experiments.